Cast explosive composition and method

Abstract

The present invention relates to a cast explosive composition and other energetic compositions such as propellants. (As used herein, the term "explosive" also shall include other energetic compositions such as propellants.) More particularly, the invention relates to a cast explosive composition which is initially formed as a stable, fluid, water-containing, water-in-oil emulsion explosive and which thereafter solidifies upon the addition of a desiccant and/or emulsion destabilizing agent. As used herein, the term "desiccant" means a water reacting, absorbing or adsorbing agent. One method of the present invention is the formulating of the cast explosive composition by adding the desiccant and/or destabilizing agent to a stable emulsion to cause the emulsion to solidify. Alternatively, a desiccant can be included in the aqueous phase of the stable emulsion which then is solidified by the addition of an emulsion destabilizing agent. A further method relates to the loading of a container with the cast explosive composition. As used herein, the terms "cast" and "solidify" refer to an unflowable or relatively unextrudable mass of finely knitted oxidizer salt crystals which have crystallized from an aqueous solution.

What is claimed is: 
     
       1. A method of formulating a cast explosive composition comprising forming a stable, fluid, water-containing, water-in-oil emulsion explosive and adding a desiccant in an amount sufficient to cause the emulsion explosive to solidify. 
     
     
       2. A method of formulating a cast explosive composition comprising (a) forming a stable, fluid, water-containing, water-in-oil emulsion explosive having a continous oil phase and a discontinuous aqueous phase and containing a desiccant dissolved in the discontinous aqueous phase and (b) adding an emulsion destabilizing agent in an amount sufficient to cause the emulsion explosive to solidify. 
     
     
       3. A method of formulating a cast explosive composition comprising forming a stable, fluid, water-containing, water-in-oil emulsion explosive and adding a desiccant and an emulsion destabilizing agent in amounts sufficient to cause the emulsion explosive to solidify. 
     
     
       4. A method of formulating a cast explosive composition comprising forming a stable, fluid, water-containing, water-in-oil emulsion explosive and adding an emulsion destabilizing agent in an amount sufficient to cause the emulsion explosive to solidify. 
     
     
       5. A method according to claims 1, 2 or 4 wherein the emulsion explosive is formulated at an elevated temperature and allowed to cool prior to adding the desiccant or emulsion destabilizing agent. 
     
     
       6. A method according to claim 3 wherein the emulsion explosive is formulated at an elevated temperature and allowed to cool prior to adding the desiccant and emulsion destabilizing agent. 
     
     
       7. A method according to claims 1, 2, 3 or 4 wherein the emulsion explosive has an emulsion phase comprising an aqueous solution of inorganic oxidizer salt, organic fuel, and a water-in-oil emulsifier. 
     
     
       8. A method according to claim 7 wherein the desiccant is a metallic nitrate, perchlorate, chlorate, sulfate, hydrogen sulfate, chloride, phosphate, carbonate or acetate salt; silica, alumina or charcoal; magnesium or calcium oxide; or an acid anhydride, acid halide, isocyanate or ester. 
     
     
       9. A method according to claims 1, 2, 3 or 4 wherein the cast explosive composition contains a particulate fuel. 
     
     
       10. A method according to claim 9 wherein the particulate fuel is metallic or carbonaceous particles. 
     
     
       11. A method according to claims 1, 2, 3 or 4 wherein the cast explosive composition contains particulate oxidizer salt. 
     
     
       12. A method according to claims 1, 2, 3 or 4 wherein the cast explosive composition contains a sensitizer. 
     
     
       13. A method according to claim 12 wherein the sensitizer is a compound explosive. 
     
     
       14. A method according to claim 13 wherein the emulsion explosive is formulated at an elevated temperature and allowed to cool prior to adding the compound explosive. 
     
     
       15. A method according to claim 12 wherein the sensitizer is hollow particles, entrained gas or gas generated in situ. 
     
     
       16. A method according to claim 7 wherein the water is present in an amount of at least 1% by weight of the emulsion phase to about 10%. 
     
     
       17. A method according to claims 2, 3 or 4 wherein the emulsion destabilizing agent is alkyl, aryl or alkyl aryl sulfonates, phosphates, carboxylates, amines, alcohols, polyalcohols, esters and amides or ethoxylated derivatives thereof; clays, aluminas or silicas; or alcohols, ethers, esters, ketones or organic acids. 
     
     
       18. A method of loading a container with a cast explosive composition comprising first forming at an elevated temperature a stable, fluid, water-containing, water-in-oil emulsion explosive; allowing or causing the emulsion explosive to cool; then adding and mixing throughout the emulsion explosive a desiccant and/or emulsion destabilizing agent in an amount sufficient to cause the emulsion explosive to solidify; and loading the container with the emulsion explosive before the desiccant and/or emulsion destabilizing agent cause the emulsion explosive to solidify. 
     
     
       19. A method of loading a container with a cast explosive composition comprising first forming at an elevated temperature a stable, fluid, water-containing, water-in-oil emulsion explosive having a continous oil phase and a discontinuous aqueous phase and containing a desiccant dissolved in the aqueous phase; allowing the emulsion explosive to cool to ambient temperature; then adding and mixing throughout the emulsion explosive an emulsion destabilizing agent; and then loading the container with the emulsion explosive before the emulsion destabilizing agent and desiccant cause the emulsion explosive to solidify. 
     
     
       20. A cast explosive composition formed from a stable, fluid water-in-oil emulsion explosive comprising inorganic oxidizer salt, water, organic fuel, a water-in-oil emulsifier and a desiccant in an amount sufficient to cause the emulsion explosive to solidify. 
     
     
       21. A cast explosive composition formed from a stable, fluid water-in-oil emulsion explosive comprising inorganic oxidizer salt, water, organic fuel, a water-in-oil emulsifier and an emulsion destabilizing agent in an amount sufficient to cause the emulsion explosive to solidify. 
     
     
       22. A cast explosive composition according to claims 20 or 21 wherein the inorganic oxidizer salt is ammonium, alkali and alkaline earth metal nitrates, chlorates, perchlorates or mixtures thereof. 
     
     
       23. A cast explosive composition according to claim 20 including an emulsion destabilizing agent. 
     
     
       24. A cast explosive composition according to claims 21 or 23 wherein the emulsion destabilizing agent is alkyl, aryl or alkyl aryl sulfonates, phosphates, carboxylates, alcohols, polyalcohols, esters, amides, acids, amines or ethoxylated derivatives thereof; clays, aluminas or silicas; or alcohols, ethers, esters, ketones or organic acids. 
     
     
       25. A cast explosive composition according to claims 20 or 21 wherein the organic fuel is mineral oil, paraffin oils and waxes, microcrystalline waxes or fuel oil and other organic distillates. 
     
     
       26. A cast explosive composition according to claims 8 or 19 wherein the emulsifier is sorbitan fatty acid esters, glycol esters, substituted oxazolines, alkyl amines or their salts or derivatives thereof. 
     
     
       27. A cast explosive composition according to claim 20 wherein the desiccant is a metallic nitrate, perchlorate, chlorate, sulfate, hydrogen sulfate, chloride, phosphate, carbonate or acetate salt; silica, alumina or charcoal; magnesium or calcium oxide; or acid anhydride, acid halide, isocyanate or ester. 
     
     
       28. A cast explosive composition according to claims 20 or 21 including a particulate fuel. 
     
     
       29. A cast explosive composition according to claim 28 wherein the particulate fuel is metallic or carbonaceous particles. 
     
     
       30. A cast explosive composition according to claim 29 wherein the metallic particles are aluminum. 
     
     
       31. A cast explosive composition according to claims 20 or 21 including particulate inorganic oxidizer salt. 
     
     
       32. A cast explosive composition according to claims 20 or 21 including a sensitizer. 
     
     
       33. A cast explosive composition according to claim 32 wherein the sensitizer is a compound explosive. 
     
     
       34. A cast explosive composition according to claims 20 or 21 including hollow particles, entrained gas or gas generated in situ as a density reducing agent. 
     
     
       35. A cast explosive composition according to claims 20 or 21 wherein the water is present in an amount of at least 1% by weight. 
     
     
       36. A cast explosive composition formed from a stable, fluid, water-containing, water-in-oil emulsion explosive comprising inorganic oxidizer salt primarily consisting of a nitrate salt or salts in an amount of from about 35% to about 95% by weight of the total composition, water in an amount of from at least about 1% to about 10%, organic fuel in an amount of from about 2% to about 15%, water-in-oil emulsifier in an amount of from about 0.2% to about 5%, a desiccant in an amount of from about 0.5% to about 5% and an emulsion destabilizing agent in an amount of from a trace to about 15%.